Sphingid larvae on Kallstroemia sp. (Caltrop) Zygophyllaceae (Creosote-Bush Family)
Dog Canyon, Otero County, New Mexico

A small Sphingid larvae on Caltrop, 8-18-2008

A size perspective

A larger Sphingid larvae on Caltrop, 8-23-2008  This one marked very much like Manduca quinquemaculata, but colored much differently, in gorgeous blue and torquise.

A size perspective

I didn't know what these small larvae could be, and I couldn't find any larvae Sphingidae listed for this host, or host family. However, they are marked like
Manduca quinquemaculata

Green morph larvae Manduca quinquemaculata  on the "normal" host, Tomato (Solanaceae) Nightsade family

Brown morph larvae Manduca quinquemaculata  on the" host, Datura quercifolia (Solanaceae)  Nightsade family
So, is the larvae on on Caltrop, Manduca quinquemaculata, adapted to this completely different host, and host family, or a similar "stealth" species.
images copyright Bob Barber